Abstract
A method that delivers a high yield and excellent quality of essential oil, which retains most of its value-added compounds, and undergoes least change after the extraction process, is greatly sought after. Although chemical free methods are acceptable, they call for an extensive processing time, while the yield and quality from these methods are often disappointing. This work utilizes subcritical water technology to address these issues. In this undertaking, essential oil was extracted from Aquilaria malaccensis wood by way of subcritical conditions, and characterized through gas chromatography/mass spectroscopy (GC/MS). Optimization through response surface methodology revealed temperature to be the most critical factor for the extraction process, while the optimum conditions for temperature, sample-to-solvent ratio, and time for subcritical water extraction was revealed as 225 °C, 0.2 gr/mL, and 17 min, respectively. The subcritical water extraction technique involves two simultaneous processes, which are based on good fitting to the two-site kinetic and second order model. In comparison to the hydrodistillation method, GC/MS results indicated that the quality of A. malaccensis’ wood oils, derived through the subcritical water technique, are of significantly better quality, while containing many constructive value-added compounds, such as furfural and guaiacol, which are useful for the production of pesticides and medicines. Pore size, functional groups, and morphology analysis revealed the occurrence of substantial damage to the samples, which facilitated an improved extraction of bio-products. In comparison to conventional methods, the use of the subcritical method not only involves a shorter processing time, but also delivers a higher oil yield and quality.
Highlights
Of late, the anti-parasitical, bactericidal, fungicidal, cosmetic, pesticide, food additive, perfumery, and medicinal possibilities of essential oils, has gained much attention globally [1]
Prior to the extraction process, the wood was soaked in water for seven days, in order to speed up the release of essential oil
The results indicate that when the amount of sample and water is sufficient, and the temperature is raised to 250 ◦ C, more essential oil is extracted from the wood
Summary
The anti-parasitical, bactericidal, fungicidal, cosmetic, pesticide, food additive, perfumery, and medicinal possibilities of essential oils, has gained much attention globally [1]. The utilization of the SCWE method, for the extraction of essential oil from Aquilaria crassna, under subcritical conditions (100, 125, and 150 ◦ C), resulted in a higher yield of A. crassna oils in a shorter time period, in comparison to the utilization of hydrodistillation [16]. These findings suggest that in terms of time, yield, and quality, the SCWE method could represent a better alternative to the currently available conventional methods, for the extraction of A. malaccensis’ oil.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
